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ExtremeTech Wages War of the Codecs
prostoalex writes "ExtremeTech tested Windows Media, DivX, QuickTime/Sorenson and QuickTime/MPEG4 codecs. They encoded clips from Matrix Reloaded, Monsters, Inc., X2 and Spider-Man. QuickTime/Sorenson won the encoding speed contest, for the quality tests read the entire review, as each movie sample was encoded with 500KB and 1MB bitrates. Video samples provided on the site as well, so see for yourself."
I'm suprised XviD, an open source, MPEG-4 compliant codec wasn't tested. It's quickly becoming a standard for the transfer of large movies, and its open source nature has all of the usual benefits: alternatives, power and no constraints or adware. I suggest anyone planning on encoding video seriously considers it. XviD.org
Here's their most recent codec shootout with 3ivx, Divx, ffvfw, Nero, Real, On2 and Xvid. Xvid wins.
Episode 4 in Ascii-mation
mplayer can do that with the aalib output plugin.
Did you read the *whole* article? They state very plainly at the end that "DivX encoded clips tended to have a touch more detail, but also a few more compression artifacts, than the WMV9 video" and that DivX encodes much faster than WMV9. In brief, the only reason for choosing WMV9 over DivX is that it may be included in upcoming consumer devices.
Good people do not need laws to tell them to act responsibly, while bad people will find a way around the laws-Plato
Well, seeing how bad ET's iTunes Bad, WMA Good article was, I figure Doom9's codec comparison is better than this.
And yes, Doom9's comparison includes XViD.
STUPID! YOU'RE SO STUPID!!!
Karma: Excellent (fuck, even in the future moderation doesn't work!)
That was a pretty tremendous scene for what it was. I thought they could've called the movie "The Rack of Kirsten Dunst"
this page has quite a shot, though this is the one people usually think of, with the webslinger getting an upsidedown kiss.
SO YOU'RE GOING TO DIE: The Comic for Dealing with Death
One thing the article and most people here seem to miss is DivX *IS* MPEG4. XviD is as well - that's why a MPEG4 decoder like ffdshow can play them both.
The article can really give people the wrong idea - it's not the MPEG4 codec, but maybe Apple's implementation that's to blame. Perhaps it just doesn't support all of MPEG4's features. Then again, perhaps the people doing the review just didn't know how to set up the encoder properly. Regardless of codec, there's quite an art to good encoding.
Please expand and explain AVC and ASP. I'll Google it myself, but for the sake of everybody...
Well, if you want a somewhat technical explanation, I would recommend reading This (warning, PDF). Very well written, with enough technical details to satisfy the casually interested geek, while readible enough for non-geeks to get the general idea.
For just the quick-and-dirty... The MPEG4 AVC (aka MPEG4 part 10, aka H.26L aka H.264.10) includes quite a few new techniques at every step of the encoding, from preprocessing to interframe prediction to new frame types to new residual handling methods. These make encoding a lot more CPU intensive, but produce considerably better results (Oddly, most sources claim only 40-50% better than MPEG2, which I find absurd, since even ASP encoders manages to do better than that).
It may help some people to better appreciate the difference by seeing some side-by-side comparisons (not exactly the best possible test conditions, but they make their point)... Balooga has a brief overview of the MPEG4 AVC vs the ASP and even MPEG2 available... Check out the screen shots, in particular.
Interstingly, on the topic of nomenclature, I think it would make people far less confused if we all called it H.264.10, rather than MPEG4 AVC. Up to and including what we normally think of as MPEG4 (the MPEG4-2 ASP), all the MPEG versions remained backward compatible. An MPEG1 stream counts as a valid MPEG2 stream, and an MPEG2 stream counts as a valid MPEG4-2 ASP stream. The AVC standard, however, departed from that backward compatibility. Not necessarily a bad idea, but by not picking a new name, everyone seem rather confused about exactly which names refer to which standards (similar to USB2, but worse, because each version has several sub-versions).
Okay, so I AM the world's leading expert on video compression codecs and formats (no, really, I am). I cover the same ground in my book, and in a series of articles for DV magazine over the last five years. So I'm pretty picky on this kind of things. But these guys couldn't compress themselves out of a wet paper bag.
Some fundamental errors:
They're using MPEG-2 sources, which are already highly compressed (this has been amply covered by other posters).
They talk about converting to an "uncompressed" AVI, but never specify which flavor of uncompressed. They should have used a lossless codec that uses the native Y'CbCr color space of video, like Huffyuv. They way they just said "uncompressed" suggests they used the AVI "None" codec, which is uncompressed RGB. This causes two lossly color space conversions - one from the Y'CbCr of the source to RGB, and then back to Y'CbCr in the delivery codec.
They used Indeo 5.1 as their intermediate codec. This is terrible. Indeo uses what's called YUV-9 sampling. There is only one measurement of color per 4x4 block of pixels. This throws away 75% of the color information from the DVD (which uses 4:2:0 sampling, with 2x2 blocks), before it even touches a codec. And this results in very ugly blocks whenever there are highly saturated regions with sharp contrast. So, all the output is going to look highly compressed when rendered from these intermediates, even if further compression is lossless. Look at the Spider Man test frame for an example. Notice the red blooming around the shoulders of the vocalist. And the color everywhere is very muddled. Indeo can also be slow to decode, unless it was encoded with all keyframes. And how slow it is to decode will vary with the tool, which probably added measurable error to their encoding time measurements.
They don't know the difference between Sorenson Video 3, which comes free with QuickTime, and Sorenson Video 3.3 Professional, which you have to pay for and is what Apple uses for their movie trailers. With the Pro version, critical features like B-frames and 2-pass VBR are available.
Apple's MPEG-4 encoder isn't very good - 1-pass only, tuned for speed more than quality. A file with the exact same compatibility could be made with Squeeze, Compression Master, Envivio, etcetera with MUCH better quality. And the Divx MPEG-4 codec is, of course, also MPEG-4.
They didn't use 2-pass encoding! No quality-concious encoder would ever put content on spinning disc without using 2-pass. And they didn't mention most of the other encoding settings they used, which by context I'd guess were basic defaults.
That's from an initial skim. If I spent more time with the article.
In summary, these guys spent hours and hours analyzing the results of tests, where they would have been WAY better off spending an hour asking someone who knew anything about video compression how to administer this kind of test.
Oddly enough, their results are vaguely like you'd expect - WMV9 and DivX do well, Sorenson less so, and Apple MPEG-4 at the rear. Done properly, I imagine WMV9 would have had a slight lead, and Sorenson 3 Pro would have been a lot closer to DivX. And no one uses Apple's MPEG-4 codec for content distribution. QuickTime's decoder is fine, so folks would use a professional-grade MPEG-4 encoder instead.
My video compression blog